1997 Annual Report for FS97-049
Crop Production Systems for Nonchemical Control of Reniform Nematodes
Summary
The reniform nematode is spreading rapidly in Alabama and is becoming an important constraint to cotton production. Monoculture production of cotton is partly to blame for the spread of this pest, and the consequent cost of chemical control is becoming prohibitive for many growers. In addition to the cost, chemical control is not a sustainable solution for many cotton growers.
Richard Edgar used his Producer Grant to pursue alternative control of reniform nematodes in a sustainable cotton production ecosystem. In-field comparisons of various crops in rotation with cotton were conducted in this project. In particular, the velvet bean, which was a rotational crop grown extensively in Alabama from the late 1800’s until the advent of cheap fertilizer and other agriculture chemicals in the 1940s, was tested in rotation with cotton.
In past experimental plots, velvet bean has dramatically reduced populations of bad nematodes, increased populations of good nematodes, and helped control weeds. The velvet bean crop controls weeds partly by rapid growth that smothers weeds and partly, it is believed, through allelopathic properties.
A ten acre field was divided into 128 rows. Richard Edgar planted rotations of velvet bean alone and velvet bean on trellises of corn and grain sorghum. Velvet bean is a climbing vine and the corn and grain sorghum kept the beans off the ground.
Nematode populations were reduced in all rotations but the most successful was velvet bean grown on corn. They were easier to work with because the vines were off the ground. Although the ideal rotation would be every other year, economics forced a less frequent rotation. Nevertheless, the use of velvet bean resulted in fewer applications of Temik.
Each year, soil samples for nematode analysis was collected from each strip at time of planting, mid-season (cotton) and at harvest. Data was also taken on cotton emergence, plant growth and yield of all crops.
A field day was held in August 1998 in cooperation with the Elmore County Farmers Federation Cotton Committee, the Elmore County extension office, and Auburn University. Pamphlets and fact sheets were prepared by the cooperators for distribution at this field day and in subsequent years. An article on the project was written up in Progressive Farmer magazine.